gistfile1.pl

┌─[tadzik@yavin4]─[~]
└─[%]─> perl6
> role something {}; our multi trait_mod:<is>(something $trait, $block, $arg) { .WHAT.say for $trait, $block, $arg }
trait_mod:<is>
> sub foo ($a) is something('foobar') { say "I has $a" }
No applicable candidates found to dispatch to for 'trait_mod:<is>'. Available candidates are:
:(something $trait, Any $block, Any $arg)
:(Mu $child, Role $r)
:(Routine $r, Any :default($default)!)
:(Code $block, Any $arg?, Any :export($export)!)
:(Mu $child, Mu $parent)
:(Mu $type where ({ ... }), Any :rw($rw)!)
:(Mu $type where ({ ... }), Any :hidden($hidden)!)